From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 096F8C433F5 for ; Wed, 2 Mar 2022 16:22:13 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1DAE910E1BA; Wed, 2 Mar 2022 16:22:13 +0000 (UTC) Received: from phobos.denx.de (phobos.denx.de [85.214.62.61]) by gabe.freedesktop.org (Postfix) with ESMTPS id A6CA710E1BA for ; Wed, 2 Mar 2022 16:22:11 +0000 (UTC) Received: from [127.0.0.1] (p578adb1c.dip0.t-ipconnect.de [87.138.219.28]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: marex@denx.de) by phobos.denx.de (Postfix) with ESMTPSA id 16D1A83CB4; Wed, 2 Mar 2022 17:22:07 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=denx.de; s=phobos-20191101; t=1646238129; bh=Ui0lOUccZ2U3X4byTnnIyzbyt9V+lYdEnWlNlS8j40k=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=xQ1IDrJe2puN8YVLVeP7wsBdn6JprbXOHdr5lsJiU0AVnGVPHhHTXRaX2Q9s/8JNL SM3mC4zuMSxj6pyrUFjmvUFwFzJLGYGVziNOJbHXw655i6c9zESx5W6wbuBumVCP4u NAnvlntqgf4e58hdzZSuaEiXuGbDzFaF+wcI59O1B3G48TjhrFNl1jrQUeYyFTqd9E LOFSvQvtkbdVqWtZ00OXwMxsL29nP+AfzHsQJIlJvuL1jpJEcJtfizE01EfoZ8v62p TuJK9beVnNJBvMC0+sc4Gxi/eWmMi0uTZDTnsWr+U+pACf+uNIm0x0Q34p0/Emv+wV CuFuUPWdSgwyw== Message-ID: <9c9a10ca-e6a1-c310-c0a5-37d4fed6efd6@denx.de> Date: Wed, 2 Mar 2022 17:22:07 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.6.1 Subject: Re: [RFC PATCH] drm/panel: simple: panel-dpi: use bus-format to set bpc and bus_format Content-Language: en-US To: Maxime Ripard , Max Krummenacher References: <20220222084723.14310-1-max.krummenacher@toradex.com> <20220223134154.oo7xhf37bgtvm3ai@houat> <20220302142142.zroy464l5etide2g@houat> From: Marek Vasut In-Reply-To: <20220302142142.zroy464l5etide2g@houat> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: clamav-milter 0.103.5 at phobos.denx.de X-Virus-Status: Clean X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Christoph Niedermaier , Max Krummenacher , Pengutronix Kernel Team , David Airlie , Sam Ravnborg , Sascha Hauer , dri-devel@lists.freedesktop.org, DenysDrozdov , Laurent Pinchart , Shawn Guo , Linux ARM , NXP Linux Team Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On 3/2/22 15:21, Maxime Ripard wrote: > Hi, Hi, > Please try to avoid top posting > > On Wed, Feb 23, 2022 at 04:25:19PM +0100, Max Krummenacher wrote: >> The goal here is to set the element bus_format in the struct >> panel_desc. This is an enum with the possible values defined in >> include/uapi/linux/media-bus-format.h. >> >> The enum values are not constructed in a way that you could calculate >> the value from color channel width/shift/mapping/whatever. You rather >> would have to check if the combination of color channel >> width/shift/mapping/whatever maps to an existing value and otherwise >> EINVAL out. >> >> I don't see the value in having yet another way of how this >> information can be specified and then having to write a more >> complicated parser which maps the dt data to bus_format. > > Generally speaking, sending an RFC without explicitly stating what you > want a comment on isn't very efficient. Isn't that what RFC stands for -- Request For Comment ? > That being said, what I (and I can only assume Marek) don't like is the > string encoding. Especially when the similar bus-type property uses a > integer with the various available bus options we have. Right, the string encoding isn't good. > Having an integer, with a set of defines that you would map to the > proper MEDIA_BUS_* would be more efficient and more elegant. > > That being said, the first question that needs to be answered is why > does this have to be in the DT in the first place? Because panel-simple panel-dpi , you may need to specify the bus format between the last bridge and the panel . From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A6476C433EF for ; Wed, 2 Mar 2022 16:23:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To:Subject: MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=CISJkxqiDjavQrst7CeT3tTwke2NEob0E46DMpc5n4A=; b=VcOC3vJTGWTuZ4 +/Kh/xXF12/6/KrU1s30qf6LgWP8CI/AkZPuLi23S48gH75lkDJ3k12QR1sZc6YV4kXkRa5R9DcrK qFfZMXwFP88Uw31KktDKkKapKPonBDc3pKniq46LbBNG+t4zTdU6akv2I1s5kL+DpeVXmlrj7Vn4J BZ7161C2X0PSN4TOYv98qDCCcTYEoj3weo3IRYr43b6bekXGrPpAb0xMdFT32BGxPfTj/vMr5v88N FqjyUgS1FKI2GTOmSLcqdFaxn+3/EzUhThGILsimDW17MSOz7ugE75qLFCaHzM4Fc8VEXL8v/YOkG NTXZaDLfrWZbxDPKxXMQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nPRk0-003Jt8-Op; Wed, 02 Mar 2022 16:22:16 +0000 Received: from phobos.denx.de ([2a01:238:438b:c500:173d:9f52:ddab:ee01]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nPRjw-003JsE-SU for linux-arm-kernel@lists.infradead.org; Wed, 02 Mar 2022 16:22:14 +0000 Received: from [127.0.0.1] (p578adb1c.dip0.t-ipconnect.de [87.138.219.28]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: marex@denx.de) by phobos.denx.de (Postfix) with ESMTPSA id 16D1A83CB4; Wed, 2 Mar 2022 17:22:07 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=denx.de; s=phobos-20191101; t=1646238129; bh=Ui0lOUccZ2U3X4byTnnIyzbyt9V+lYdEnWlNlS8j40k=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=xQ1IDrJe2puN8YVLVeP7wsBdn6JprbXOHdr5lsJiU0AVnGVPHhHTXRaX2Q9s/8JNL SM3mC4zuMSxj6pyrUFjmvUFwFzJLGYGVziNOJbHXw655i6c9zESx5W6wbuBumVCP4u NAnvlntqgf4e58hdzZSuaEiXuGbDzFaF+wcI59O1B3G48TjhrFNl1jrQUeYyFTqd9E LOFSvQvtkbdVqWtZ00OXwMxsL29nP+AfzHsQJIlJvuL1jpJEcJtfizE01EfoZ8v62p TuJK9beVnNJBvMC0+sc4Gxi/eWmMi0uTZDTnsWr+U+pACf+uNIm0x0Q34p0/Emv+wV CuFuUPWdSgwyw== Message-ID: <9c9a10ca-e6a1-c310-c0a5-37d4fed6efd6@denx.de> Date: Wed, 2 Mar 2022 17:22:07 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.6.1 Subject: Re: [RFC PATCH] drm/panel: simple: panel-dpi: use bus-format to set bpc and bus_format Content-Language: en-US To: Maxime Ripard , Max Krummenacher Cc: dri-devel@lists.freedesktop.org, Sascha Hauer , Philipp Zabel , Laurent Pinchart , Fabio Estevam , Linux ARM , DenysDrozdov , David Airlie , Christoph Niedermaier , Pengutronix Kernel Team , Sam Ravnborg , Shawn Guo , Daniel Vetter , NXP Linux Team , Max Krummenacher References: <20220222084723.14310-1-max.krummenacher@toradex.com> <20220223134154.oo7xhf37bgtvm3ai@houat> <20220302142142.zroy464l5etide2g@houat> From: Marek Vasut In-Reply-To: <20220302142142.zroy464l5etide2g@houat> X-Virus-Scanned: clamav-milter 0.103.5 at phobos.denx.de X-Virus-Status: Clean X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220302_082213_311100_5BE7EF4E X-CRM114-Status: GOOD ( 21.06 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 3/2/22 15:21, Maxime Ripard wrote: > Hi, Hi, > Please try to avoid top posting > > On Wed, Feb 23, 2022 at 04:25:19PM +0100, Max Krummenacher wrote: >> The goal here is to set the element bus_format in the struct >> panel_desc. This is an enum with the possible values defined in >> include/uapi/linux/media-bus-format.h. >> >> The enum values are not constructed in a way that you could calculate >> the value from color channel width/shift/mapping/whatever. You rather >> would have to check if the combination of color channel >> width/shift/mapping/whatever maps to an existing value and otherwise >> EINVAL out. >> >> I don't see the value in having yet another way of how this >> information can be specified and then having to write a more >> complicated parser which maps the dt data to bus_format. > > Generally speaking, sending an RFC without explicitly stating what you > want a comment on isn't very efficient. Isn't that what RFC stands for -- Request For Comment ? > That being said, what I (and I can only assume Marek) don't like is the > string encoding. Especially when the similar bus-type property uses a > integer with the various available bus options we have. Right, the string encoding isn't good. > Having an integer, with a set of defines that you would map to the > proper MEDIA_BUS_* would be more efficient and more elegant. > > That being said, the first question that needs to be answered is why > does this have to be in the DT in the first place? Because panel-simple panel-dpi , you may need to specify the bus format between the last bridge and the panel . _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel